How to Control Cabbage Worms in the Garden

How to Control Cabbage Worms in the Garden

Cole Crops

If you’re growing Cole crops such as cabbage, broccoli, kale or Brussel sprouts, your garden is probably a habitat for the cabbage butterfly and its offspring, the infamous cabbage worm. To eradicate cabbage worms in your garden you must understand them.


Cabbage worms are the larval stage of the cabbage white butterfly. You have probably seen this small white butterfly flying around your garden and stopping momentarily to land on a plant here and there. That split second is all time needed for the butterfly to deposit eggs on each plant it visits. The eggs will quickly hatch in five to seven days into a green leaf eating caterpillars that will devourer your plants. Despite the significant damage the caterpillars can cause, they are relatively easy to control. Let’s look at some options you can use to keep these crawling pests from ruining your crops.


Because of their hearty appetite, it only takes a few worms to cause damage to your plants. Look for holes being chewed in the leaves of your plants, or entry holes into the heads of cabbage, or in the florets of broccoli. The cabbage worm is a green, inchworm-type caterpillar that is roughly one inch long.

Floating Row Covers

To prevent cabbage worm infestations, protect your plants with Harvest Guard Floating Row Covers, especially in early spring and summer when egg laying activity is at its highest. This ultra-light cover “floats” over plants to give them protection from the cabbage butterfly from laying eggs on the plant. You can also handpick the cabbage worms and caterpillars from the plant, this is an easy method if you have just a few plants and the caterpillars haven’t become too numerous to hand pick.

Bacillus Thuringiensis

For severe infestations or larger gardens, you may need to use other means to control the caterpillars. A popular caterpillar control is Bacillus Thuringiensis, commonly known as BT. The great thing about BT is that it only affects insects that are in the caterpillar stage. The caterpillars stop feeding and die within 2-3 days of ingestion. BT may be applied up until the day of harvest. Apply BT to all parts of the plants, be sure to repeat the application after a heavy rain, or if washed off by watering your plants. BT can be applied with either a hose-end or tank sprayer. Always read the label and follow the directions for recommended use.

Insecticidal Soap

Another good natural product for controlling numerous pests, including the cabbage worm, is insecticidal soap. Insecticidal soap is a contact killer. It penetrates the body of pest and results in rapid death. Insecticidal soap works best on soft-bodied insects, aphids, mealy bugs, mites and many other insects. Because insecticidal soap is a contact killer, you must thoroughly spray insects for best results. Always read the label and follow the directions for recommended use.


Zamzows Z-One insect control is effective against cabbage worms as well as over 100 different types of insects. It is available in a ready-to-use spray bottle, a hose-n-go applicator, or in concentrated form. Zamzows Z-One can be used on vegetables, fruits, ornamentals and trees and shrubs. Always read the label and follow the directions for recommended use.